A dust collector, also known as a vacuum cleaner, is commonly used household cleaning equipment where dust and chippings are sucked into a dust bucket through working airflow and then the working airflow is exhausted. Therefore, the dust collector needs to have a function of separating working airflow, dust and chippings from air. So far, a filtering device is the most commonly used and effective solution of realizing air and dust separation. The filtering device needs to be frequently dismantled from the dust collector during use. For example, the filtering device of the dust collector, after being used for a period of time and on which a large amount of dust may be accumulated, needs to be dismantled for cleaning and then remounted. In some designs, a filtering member of the filtering device is made of filter paper. After the filter paper is used for a period of time, the surface of the filter paper is accumulated with a large amount of dust, at this moment, the filter paper needs to be replaced so as to ensure normal running of the dust collector. If the filter paper and the filtering device cannot be easily dismantled, therefore, both need to be replaced together. Publication No. CN101711657 discloses a replaceable filtering device which comprises a filtering device rack and which is sheathed on the rack, wherein an elastic end cap on which an end hole is provided is disposed on one end of the filtering device, and wherein when the filtering device is mounted, a support column on the rack penetrates the end hole and enables the end hole to be kept in a region of the support column having a smaller outer diameter. Since mounting and fixing are finished through the elastic end hole in the solution aforementioned, the elastic structure will generate problems of structure aging, elasticity failure or the like after being dismantled, mounted and used repeatedly for a relatively long time. Therefore, the filtering device will possibly fall off in use in case of structure aging or elasticity failure, and moreover, the elastic end cap and the support post are inconvenient to mount and dismantle because of an interference fit there between.